| 摘要 |
PURPOSE:To enable a controller for brushless DC motors provided with a current control system which performs PWM control on the output voltage of an inverter to stably make controlling operations by eliminating a change in the responsiveness of the current control system resulting from a change in the rotating speed of a motor and preventing the saturation of the current control system against the DC voltage variation of the inverter. CONSTITUTION:A change in the rotating speed of a motor is compensated by adding voltage command signals Vu, Vv, and Vw corresponding to the rotating speed of the motor from an arithmetic circuit 20 for computing three-phase voltages to voltage commands from current controlling amplifiers 71 and 72 so as to eliminate the responsiveness variation of a current control system. In addition, when the current control system starts to cause saturation, a stable controlled state is set by controlling a change-over switch 21 to a turned-off state by means of a turning on/off signal from a change-over control circuit 19, switching the control to voltage control by means of the voltage command signals Vu, Vv, and Vw from the circuit 20 side, and limiting a voltage command value V1' to the maximum output voltage value V1max of an inverter. |
